An upperclassman quickly sketches a graph packed with logarithms and absolute values; an underclasswoman marvels at his speed — and seeks shortcuts. Doctor Douglas walks through his routine for plotting curves, and along the way exploits symmetries that conserve effort.

A teacher seeks an explanation for why slope is "rise over run" rather than "run over
rise." Doctor Peterson reveals the logic, as well as a way to investigate these kinds of
imponderables, before affirming her derivation from slope-intercept form and
suggesting related motivations from other applications.